CN106800911A - A kind of composite modified gluing agent of MG resin plant albumen and preparation method and application - Google Patents

Abstract

The present invention provides a kind of composite modified gluing agent of MG resin plant albumen and preparation method and application.The active component of the composite modified gluing agent includes the vegetable protein dregs of rice, MG resins.Adhesive water-tolerant prepared by the present invention, solids content is high, and has good toughness simultaneously, the advantages of manufacturing process is simple and environmentally-friendly pollution-free, do not exist Form aldehyde release problem with its wood-based plate being glued, it is to avoid the Formaldehyde in room air caused by wood-based plate.

Description

A kind of MG resin vegetable protein composite modified adhesive and its preparation method and application

technical field

The invention belongs to the field of wood adhesives, and in particular relates to an MG resin vegetable protein composite modified adhesive and a preparation method and application thereof.

Background technique

The consumption of wood adhesives continues to increase, among which aldehyde adhesives still dominate wood adhesives. However, "aldehyde" adhesives are not environmentally friendly products. During the production and use of adhesives and their products, toxic gases such as formaldehyde and phenol will be released, causing environmental pollution and seriously threatening people's health. In addition, the raw materials in aldehyde adhesives come from non-viable resources such as petroleum and coal. With the gradual depletion of fossil resources and people's increasing concern for environmental protection, research and development of renewable, applicable and environmentally friendly wood Adhesives are an important issue facing the wood industry.

Considering that plant protein is the main by-product of bulk agricultural product processing, it has abundant sources and is renewable. Among them, soybean protein shows great development potential due to its cheap price and the environmental protection and convenience of production, transportation and use of soybean protein adhesives prepared. As a renewable resource-based biomass adhesive and environmentally friendly biomaterial, soybean protein-based adhesives can not only reduce environmental pollution, but also use resources efficiently, responding to the global sustainable development strategy, so it is increasingly It has been paid more and more attention, and has gradually become a research hotspot. Due to the presence of a large number of hydrophilic groups on the protein molecular structure, such as hydroxyl (-OH) amino (-NH ₂ ), and the extremely weak intermolecular bonding, the traditional cross-linking modification has low reactivity and low efficiency. As a result, plant adhesives usually have outstanding problems such as poor water resistance, high viscosity, and low solid content.

Contents of the invention

The purpose of the present invention is to provide a kind of MG resin plant protein composite modified adhesive and its preparation method and application, the adhesive solves the problem of traditional aldehyde resin modified biomass adhesive containing formaldehyde, does not contain formaldehyde at all Formaldehyde and other aldehydes are highly efficient and environmentally friendly adhesives, especially suitable for adhesives for veneer-based wood-based panels.

The technical scheme that realizes the above-mentioned purpose of the present invention is:

An MG resin vegetable protein composite modified adhesive, the active ingredient includes vegetable protein meal and MG resin (namely, melamine-glyoxal co-condensation resin).

Preferably, the active ingredient of the MG resin vegetable protein composite modified adhesive includes the following components by weight: 20-40 parts of vegetable protein meal, and 1-10 parts of MG resin.

Further preferably, the active ingredient of the MG resin vegetable protein composite modified adhesive includes the following components by weight: 25-35 parts of vegetable protein meal, and 1.3-3.5 parts of MG resin.

Further, the raw material of the MG resin vegetable protein composite modified adhesive also includes water (the main purpose is to be used as a solvent); further, the total amount of the MG resin vegetable protein composite modified adhesive is 100 parts , make up the balance with water.

The water may be one or more of tap water, demineralized water, and deionized water, and tap water may be used in industrial production.

One of the embodiments of the present invention: an MG resin vegetable protein composite modified adhesive, which includes the following components in parts by weight: 20-40 parts of vegetable protein meal, 1-10 parts of MG resin, and 60-80 parts of water.

Further preferably, the MG resin vegetable protein composite modified adhesive comprises the following components in parts by weight: 25-35 parts of vegetable protein meal, 1.3-3.5 parts of MG resin, and 65-75 parts of water.

The present invention finds that when the vegetable protein meal and MG resin are within the range of the above-mentioned dosage ratio, it has better adhesive effect.

In order to prolong the shelf life, the modified vegetable protein adhesive of the present invention may also include an appropriate amount of preservatives.

The vegetable protein meal in the present invention includes one or a mixture of distiller's grains, cotton meal, peanut meal, sunflower meal and the like. The vegetable protein meal can be prepared according to conventional methods in the art, and generally refers to the processing residue of edible oil production.

The vegetable protein meal of the invention contains 35-45% of crude protein and sugars in different quantities, wherein the protein molecule reacts with the modified component MG resin to obtain a high-strength adhesive.

Preferably, the vegetable protein meal is pulverized to a particle size above 100 mesh.

A preparation method of the vegetable protein meal is to clean soybeans, cottonseeds, peanuts, sunflowers, etc., after cleaning, tempering, cracking, peeling, and tableting, then degrease or physically press them with the organic solvent n-hexane and similar hydrocarbons, etc. , and then dried and pulverized into a powder.

The MG resin can be prepared according to the methods of the prior art, or commercially available products can be purchased.

A specific preparation method of MG resin is provided below:

(1) In a reaction kettle equipped with a stirrer, add a certain proportion of melamine and glyoxal, add p-toluenesulfonic acid dropwise, adjust the pH value to 7.5-8.5, and stir evenly;

(2) Heat up to 70°C, add melamine and stir evenly, adjust the pH value to 5.5, and react for 1 hour;

(3) Adjust the pH value to 7.0, lower the temperature to 40° C., and discharge to obtain MG resin.

The present invention also provides a preparation method of the above-mentioned MG resin vegetable protein composite modified adhesive, comprising the following steps:

S1 In a reaction kettle equipped with a stirrer, add water and vegetable protein meal (powder) according to the proportion and stir evenly;

S2 Add MG resin according to the ratio (or add an appropriate amount of preservative) and stir evenly to obtain vegetable protein mucus;

In S3, the obtained vegetable protein mucus is processed through a colloid mill and a homogenizer, and the pressure of the homogenization processing is 20-40 MPa.

The method of the invention has simple process and convenient operation. The prepared adhesive has good water resistance, high solid content, good toughness, low manufacturing cost, renewability, environmental protection and no pollution. The problem of formaldehyde in indoor air caused by boards.

The present invention also includes the application of the MG resin vegetable protein composite modified adhesive in wood processing.

The present invention also includes processed wood products containing the above-mentioned MG resin vegetable protein composite modified adhesive.

Beneficial effects of the present invention:

1) The main component of the modified vegetable protein adhesive prepared by the present invention is vegetable protein meal, which has the advantages of low viscosity, high solid content, good adhesive layer toughness, and can be supplied in large quantities, and the formaldehyde emission of glued plywood is equivalent to that of Compared with the aldehyde resin modified protein adhesive, it has obvious advantages, and it is basically equivalent to solid wood, which completely solves the problem of formaldehyde pollution in the indoor air caused by wood-based panels. The modified vegetable protein adhesive of the present invention is especially suitable for the modified vegetable protein adhesive of veneer wood-based panels.

2) Melamine-glyoxal (MG) resin has the advantages of high reactivity, low viscosity, good toughness, and no release of free formaldehyde. Using MG as a cross-linking agent to prepare a modified vegetable protein-based wood adhesive, the construction has a certain toughness. The cross-linking system integrated with rigidity can greatly improve the water resistance and other properties of the modified soybean protein-based adhesive. By forming a composite cross-linking system with MG resin, the highly reactive triazine nitrogen-containing heterocyclic network structure can be effectively introduced into the modified vegetable protein adhesive, which can greatly improve the cross-linking density and water resistance of the cured product. , Significantly increase the solid content of the protein adhesive. The experimental results show that the bonding strength of the plywood prepared by the modified adhesive can fully meet the requirements of the national standard for Class II plywood, and the formaldehyde emission has not been detected.

detailed description

The following examples are used to illustrate the present invention, but are not intended to limit the scope of the present invention.

Vegetable protein meal was purchased from Shandong Xiangchi Grain and Oil Co., Ltd., with a protein content ≥ 43%, which was crushed and passed through a 100-mesh sieve.

The colloid mill model JMS-110 was purchased from Langfang Guantong Machinery Co., Ltd. The homogenizer is the supporting equipment of the same manufacturer.

In the embodiments, unless otherwise specified, the means used are conventional technical means in the art.

Example 1

A MG resin vegetable protein composite modified adhesive comprises the following components: 75Kg of tap water, 25Kg of defatted vegetable protein meal powder, and 1.3kg of MG resin.

The preparation method comprises the following steps:

S1 In a reaction kettle equipped with a stirrer, a thermometer and a condensing device, add water and vegetable protein meal (powder) according to the proportion and stir evenly; the reaction is carried out at normal temperature;

S2 Add MG resin according to the proportion and stir evenly to make vegetable protein mucus;

In S3, the obtained vegetable protein slime is processed through a colloid mill and a homogenizer, and the pressure of the homogenization processing is 25 MPa.

Three batches of parallel samples were prepared by the same process, and the performance and quality indicators of the obtained adhesives are shown in Table 1.

Example 2

A MG resin vegetable protein composite modified adhesive comprises the following components: 65Kg of tap water, 30Kg of defatted vegetable protein meal powder, and 2.4kg of MG resin.

The preparation method is the same as in Example 1.

Three batches of parallel samples were prepared in the same way, and the performance and quality indicators of the prepared adhesive are shown in Table 1.

Example 3

A MG resin vegetable protein composite modified adhesive comprises the following components: 65Kg of tap water, 35Kg of defatted vegetable protein meal powder, and 3.5kg of MG resin.

The preparation method is the same as in Example 1.

Three batches of parallel samples were prepared in the same way, and the performance and quality indicators of the prepared adhesive are shown in Table 1.

Table 1 Performance Index of Vegetable Protein Adhesive

The storage period of the prepared adhesive samples is 3-5 days (after 3-5 days of storage at low temperature (4°C), there will be local mildew or odor, but the bonding performance will not be affected).

Comparative example 1

An adhesive comprises the following components: 75 parts by weight of tap water, and 25 parts by weight of defatted vegetable protein meal powder.

The preparation method is the same as in Example 1.

Comparative example 2

An adhesive comprises the following components: 65 parts by weight of tap water, and 30 parts by weight of defatted vegetable protein meal powder.

The preparation method is the same as in Example 1.

Comparative example 3

An adhesive comprises the following components: 65 parts by weight of tap water, and 35 parts by weight of defatted vegetable protein meal powder.

The preparation method is the same as in Example 1.

Experimental example

The adhesive products of Examples 1-3 of the present invention and Comparative Examples 1-3 were respectively used to manufacture three-layer plywood of 410×410 mm.

Poplar veneer: dry to 8-12% moisture content; thickness 1.6mm;

The veneer adhesive used the products of Examples 1-3 of the present invention and the products of Comparative Examples 1-3.

Plywood is prepared according to the normal process as follows:

Glue sizing: Glue is applied on both sides of the core board, and the amount of glue applied is 300-360g/m ² .

Aging method and time: closed aging, 10-30 minutes.

Hot pressing pressure: 1.0MPa, hot pressing temperature is 120°C, hot pressing time is 70s/mm.

According to the test method of GB/T17657-1999 "Physical and Chemical Properties of Wood-based Panels and Decorated Wood-based Panels", the performance test of the produced plywood products is carried out. The test results are shown in Table 2.

Table 2 Formaldehyde emission and bonding strength of glued plywood

Specimen Formaldehyde emission (mg/L) Bonding strength (MPa) Example 1 0.02 0.95±0.04 Example 2 0.04 1.26±0.03 Example 3 0.03 1.05±0.05 Comparative example 1 0.05 0 (open glue) Comparative example 2 0.06 0 (open glue) Comparative example 3 0.06 0 (open glue)

The experimental results show that the formaldehyde emission of the plywood made by the formaldehyde-free vegetable protein adhesive of the present invention is very low (for the release of the formaldehyde of the wood body), and the bonding strength of the plywood can reach the standard of class II plywood in the national standard (poplar wood ≥ 0.70 MPa).

Although the present invention has been described in detail with general descriptions and specific embodiments above, it is obvious to those skilled in the art that some modifications or improvements can be made on the basis of the present invention. Therefore, the modifications or improvements made on the basis of not departing from the spirit of the present invention all belong to the protection scope of the present invention.

Claims (10)

1. A kind of MG resin plant protein compound modified adhesive, its active component comprises plant protein meal, MG resin. 2. The adhesive according to claim 1, wherein the active ingredient comprises the following components by weight: 20-40 parts of vegetable protein meal, 1-10 parts of MG resin; Preferably, the active ingredients include the following components by weight: 25-35 parts of vegetable protein meal, and 1.3-3.5 parts of MG resin. 3. The adhesive according to claim 1 or 2, wherein the raw material also includes water; preferably, the total amount of the adhesive is 100 parts, and the balance is made up with water. 4. The adhesive according to claim 1, characterized in that it comprises the following components in parts by weight: 20-40 parts of vegetable protein meal, 1-10 parts of MG resin, and 60-80 parts of water; Preferably, the adhesive includes the following components in parts by weight: 25-35 parts of vegetable protein meal, 1.3-3.5 parts of MG resin, and 65-75 parts of water. 5. The adhesive according to any one of claims 1-4, further comprising an appropriate amount of preservative. 6. The adhesive according to any one of claims 1-4, characterized in that, the vegetable protein meal comprises one or a mixture of distiller's grains, cotton meal, peanut meal, and sunflower meal; Preferably, the vegetable protein meal contains 35-45% crude protein; And/or, the particle size of the vegetable protein meal is above 100 mesh. 7. The adhesive according to any one of claims 1-4, wherein the MG resin is prepared by the following method: (1) In a reaction kettle equipped with a stirrer, add a certain proportion of melamine and glyoxal, add p-toluenesulfonic acid dropwise, adjust the pH value to 7.5-8.5, and stir evenly; (2) Heat up to 70°C, add melamine and stir evenly, adjust the pH value to 5.5, and react for 1 hour; (3) Adjust the pH value to 7.0, lower the temperature to 40° C., and discharge to obtain MG resin. 8. The preparation method of the adhesive described in any one of claims 1-7, is characterized in that, comprises the following steps: S1 In a reaction kettle equipped with a stirrer, add water and vegetable protein meal (powder) according to the proportion and stir evenly; S2 Add MG resin according to the proportion and stir evenly to make vegetable protein mucus; In S3, the obtained vegetable protein mucus is processed through a colloid mill and a homogenizer, and the pressure of the homogenization processing is 20-40 MPa. 9. the application of the MG resin vegetable protein composite modified adhesive of any one of claims 1-7 in wood processing. 10. The wood processed product containing the MG resin vegetable protein composite modified adhesive according to any one of claims 1-7.